diff options
| author | Aneesh Kumar K.V | 2009-06-05 01:00:26 -0400 |
|---|---|---|
| committer | Theodore Ts'o | 2009-06-05 01:00:26 -0400 |
| commit | 1938a150c25bf7c2c47182e753a1038945b70b0e (patch) | |
| tree | cab711b2868d719c6f460a75387acf84f6b37576 /fs/ext4 | |
| parent | b31e15527a9bb71b6a11a425d17ce139a62f5af5 (diff) | |
ext4: Avoid leaking blocks after a block allocation failure
We should add inode to the orphan list in the same transaction
as block allocation. This ensures that if we crash after a failed
block allocation and before we do a vmtruncate we don't leak block
(ie block marked as used in bitmap but not claimed by the inode).
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
CC: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/inode.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 17ed0d244dbb..8d215881172f 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1459,7 +1459,7 @@ static int ext4_write_begin(struct file *file, struct address_space *mapping, struct page **pagep, void **fsdata) { struct inode *inode = mapping->host; - int ret, needed_blocks = ext4_writepage_trans_blocks(inode); + int ret, needed_blocks; handle_t *handle; int retries = 0; struct page *page; @@ -1470,6 +1470,11 @@ static int ext4_write_begin(struct file *file, struct address_space *mapping, "dev %s ino %lu pos %llu len %u flags %u", inode->i_sb->s_id, inode->i_ino, (unsigned long long) pos, len, flags); + /* + * Reserve one block more for addition to orphan list in case + * we allocate blocks but write fails for some reason + */ + needed_blocks = ext4_writepage_trans_blocks(inode) + 1; index = pos >> PAGE_CACHE_SHIFT; from = pos & (PAGE_CACHE_SIZE - 1); to = from + len; @@ -1503,15 +1508,30 @@ retry: if (ret) { unlock_page(page); - ext4_journal_stop(handle); page_cache_release(page); /* * block_write_begin may have instantiated a few blocks * outside i_size. Trim these off again. Don't need * i_size_read because we hold i_mutex. + * + * Add inode to orphan list in case we crash before + * truncate finishes */ if (pos + len > inode->i_size) + ext4_orphan_add(handle, inode); + + ext4_journal_stop(handle); + if (pos + len > inode->i_size) { vmtruncate(inode, inode->i_size); + /* + * If vmtruncate failed early the inode might + * still be on the orphan list; we need to + * make sure the inode is removed from the + * orphan list in that case. + */ + if (inode->i_nlink) + ext4_orphan_del(NULL, inode); + } } if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) |